Update on Ectopic Pregnancy - HD

Introduction

My name is Mary Frady.
I'm from Brigham and Women's Hospital in Boston.
My topic today is update on ectopic pregnancy.

Background on Ectopic Pregnancy

Let's talk about some background for ectopic pregnancy.
Ectopic pregnancy essentially means that the products
of conception have implanted outside
of the endometrial cavity.
This occurs in about one
and a half to 2% of all pregnancies.
We care about ectopic pregnancy
because complications of ectopics are the leading cause
of pregnancy related deaths during the first trimester.
In the United States, the majority
of ectopic pregnancies occur in the fallopian tube.
The ampullary portion of the tube is the most common site
with the isthmic section.
The second most common ectopics in the interstitial portion
of the fallopian tube, the so-called cornual ectopics,
cervical ectopics, ovarian ectopics, pretty rare.

Risk Factors

Who's at high risk for ectopic pregnancy?
The known risk factors are anyone with tubal scarring.
So that's a patient who's had pelvic inflammatory disease
or a prior ectopic pregnancy.
Any patient with an IUD present in the endometrial cavity,
and also the huge number of patients
who are undergoing assisted fertilization
for whatever reason for the uterus or the tubes
or the ovaries, are not working completely normally.
And those patients will be at increased risk
for ectopic pregnancy.
Now, it's interesting to remember that 25% of pregnancies
that occur in patients with an indwelling IUD
or a history of tubal ligation are ectopic pregnancies.
So when you have a positive pregnancy test in
that population, you wanna be aware
that they are high risk for ectopics.
However, even knowing that 50% of the patients
with ectopic pregnancy comes in with no known risk factor,
here's what we're talking about when I say that Patients
with history of PID
or scarring are at increased risk.
So here's the hydrosalpinx.
You can see the dilated fallopian tube.
Here's the sausage shape
or the curved fluid-filled dilated fallopian tube
and the cogwheel appearance.
And a coronal image, a transverse image
of the fallopian tube, all abnormal tubes.

Clinical Presentation and Initial Evaluation

The classic presentation of a patient
with ectopic pregnancy is pain, vaginal bleeding,
and an adnexal mass in a patient
who presents with those findings.
If there's a positive pregnancy test as well,
ultrasound should be the first test done.
And here we see a tubal ring sitting right next
to the left ovary.

Role of hCG

Let's talk about HCG.
So trophoblastic tissue makes HCG eight days
after conception.
Normally, a intrauterine gestational sac will typically be
seen with transvaginal sonography once that HCG gets
to a thousand milli international units.
However, you should be aware
that in a study done in 1997, one third of the patients with
HCGs of over 2000 ended up
with intrauterine pregnancies at follow up.
So from some data from our hospital at Brigham
and Women's, we looked at 225 patients
with ectopic pregnancies, all
of whom had their HCG drawn within 24 hours
of the transvaginal ultrasound.
The HCG in this patient series ranged from a low of seven
to a high of 107,000.
The average being around 3000,
it was significantly higher in patients
with a live ectopic pregnancy 20,980,
as opposed to patients whose ectopics did not have cardiac
activity, where the average was 1,900.
The majority of the patients in our series did have an HCG
of under 3000, but 7% had an HCG of over 10,000.

Cautionary Case

I'd like to just mention a cautionary case
that we did see recently at the Brigham,
where a patient came in with an HCG of over 4,000,
and at transvaginal sonography,
nothing was found in the uterus.
In addition, nothing was found in the adnexa.
We followed that patient up
and she ended up with a normal intrauterine pregnancy.
So it is incredibly important to realize
that patients should not be treated for an ectopic pregnancy
unless you are absolutely certain
that there is nothing in the uterus
that could potentially be a normal intrauterine pregnancy.

Pregnancy of Unknown Location

When you have a patient with a positive pregnancy test
and no pregnancy is found in the uterus on transvaginal
sonography, we term that a pregnancy of unknown location.
And in this situation, there really are only three options.
Either the pregnancy is in the uterus and it's too early
or too small for us to identify
with transvaginal sonography.
The patient could potentially have just undergone a
spontaneous loss or have a chemical pregnancy,
or there may be an ectopic pregnancy.

Identifying Intrauterine Pregnancy

So how do you know whether there's an
intrauterine pregnancy or not?
Well, an intrauterine pregnancy,
an intrauterine gestational sac is round,
has a very clear echogenic rim,
and often will have a yolk sac, a fetal pole,
or a fetal heartbeat.
It should be located within the decidua of the endometrium.
Don't be misled by fluid in the endometrial cavity.
Here's a few examples of small gestational sacs.
On the top left, you see a well-defined echogenic ring
with a little bit of free fluid in the endometrial cavity,
and you can appreciate the intradecidual location
of this gestational sac.
Bottom left image, again,
a little tiny fluid collection within the decidualized
endometrium may be too small to know for sure whether
that's a gestational sac or not.
And on the clip you can see a little bit
of a bigger fluid collection
with a white ring in the decidua endometrium.
These can either be dictated as
a small early gestational sac
or as a probable gestational sac.
Another case clearly defined echogenic rim
round sac in the decidualized endometrium
and some fluid in the endometrial cavity are likely blood.
In comparison to these three cases, we can see
that there's fluid in the endometrial cavity,
very irregular, poorly defined, a little bit
of debris in this one,
but not a discreet, well-defined circular structure
with an echogenic rim.
In these cases, no gestational sac is seen.
Some complex endometrial fluid is present.

Endometrial Thickness and Patterns

When we look at the endometrium in a patient
and we're concerned about the presence
of an ectopic or an intrauterine pregnancy, one
of the things we can look at is
how thick the endometrium is.
Is this a reasonable thing to do?
In 2008, one author showed
that if the endometrium was less than eight millimeters in
thickness, none
of those patients had an intrauterine pregnancy
At the opposite end, in the patients
with an endometrium over 25 millimeters, four patients
with ectopics did have that very thick endometrium.
Can we look at a trilaminar pattern?
The multi-layered endometrium, will that help?
When we use a multi-layered endometrium with an attempt
to predict whether there's an ectopic pregnancy
or not, has a very low sensitivity
and a positive predictive value of only 50%.
So, flipping a coin. So trilaminar pattern not that useful.

Case Example: Clomid Patient

Here's a patient who was seen recently on Clomid
by her last menstrual period.
She should be seven and a half weeks.
And when we look transvaginally, no intrauterine pregnancy is seen.
Here's the image that was submitted to us
as a normal right ovary.
This was done at one of our remote sites,
but at 7.5 weeks, we were concerned that there had
to be a pregnancy in there somewhere.
So she had the exam repeated
that afternoon at the hospital,
and here's the right ovary image that was then obtained.
You can see that the right ovary
with its corpus luteal cyst is here
and that there's a complex mass seen on the lateral
edge of the ovary.
And with a video clip, we can appreciate
that there is an embryo with cardiac
activity seen in this ectopic sitting
right next to the ovary.
So you do have to be careful.
Just one picture of an ovary does not rule out the presence
of an associated mass.

Adnexal Evaluation

Again, it's more important to identify a mass in the adnexa,
and that's the best way
to diagnose an ectopic pregnancy rather than relying on the
fact that there's nothing in the uterus.
The earlier we can find a mass,
the earlier we can take care of the patient.
So unlike the traditional non-pregnant patient
where you scan the uterus and you take a coronal
and a sag clip of one ovary and a coronal,
and a sag look at the other ovary,
that's when the study starts.
For ectopic pregnancy, you can do your standard exam
and then you have to start looking around
for anything out of the ordinary.
That could be the ectopic.
It's not going to be one of the traditional pictures
that you're taking for your pelvic ultrasound.

Case: History of Ectopic

Here's a patient who had a history of ectopic pregnancy,
who came in with her dating at 4.7 weeks with some pain
and highly concerned because of her prior history,
and we could see, here's an image of the ovary,
but just next to the ovary we could see a soft tissue
structure with blood flow just lateral to the ovary.
And on the video clip, you can see the ovary is here
and there's this structure, which was a tubular
solid appearing structure just lateral to the ovary.
This turned out to be normal fallopian tube
in this particular patient
and on follow-up, there was a normal intrauterine pregnancy.
So if the patient is stable
and the findings are not convincing, the best thing
to do is follow the patient, follow the HCG
and get a repeat ultrasound.

Tubal Ring

What are we looking for in the adnexa?
Well, the most convincing finding
for an ectopic pregnancy is the presence of a tubal ring.
A tubal ring is a round hypoechoic
or anechoic structure with an echogenic ring around it,
which is basically the gestational sac.
You can think about the sac that we looked at,
or early sacs that we looked at in the uterus, picking up
that sac and moving it out into the adnexa
and throwing it over there next to an ovary
or next to the outside of the uterus.
It's the same look, you're looking for a pregnancy sac.
25% of patients
with ectopic pregnancy in our recent series
did have a tubal ring.
8% had a tubal ring with a yolk sac,
and 7% had a tubal ring with a yolk sac
and cardiac activity.

Examples of Tubal Rings

What does the tubal ring look like?
Well, here's another patient with ectopic pregnancy.
We can see the ovary here with a corpus luteal cyst on it,
and the bright echogenic ring with an anechoic center.
Here's the yolk sac,
and when we look closely, we can see an embryo
and cardiac activity in this live ectopic.
Here's another patient. This is a coronal image
of the uterus, and you can see a beautiful intrauterine
gestational sac, pretty much anechoic center echogenic ring
around the outside and a yolk sac in the middle.
But look at this out in the left
adnexa is the identical picture.
Here's the echogenic ring, the anechoic center and the yolk sac.
And this patient has a heterotopic pregnancy with an IUP
and a left-sided ectopic pregnancy.
But it's amazing how similar the two pregnancies look.

Subtle Findings

Sometimes the findings are pretty subtle in this patient.
Here's the left ovary,
and you could see there's a little tiny,
tiny echogenic structure.
Well, it got an anechoic center
and an echogenic ring around the outside here it is measured
and here it is in the sagittal plane.
It looks a little bit bigger.
The ovaries up here, a very bright echogenic ring,
helps us know that this is a tiny early ectopic.
Sometimes we don't see the echogenic ring
and we just find a complex mass with poorly defined borders.
Very ill-defined over half
of ectopic pregnancies in our series
presented with this finding.
When you see these ill-defined complex masses,
take a really close look in the center of the mass
because you may be able to find the tubal ring or a yolk sac
or something that tells you
that this indeed is an ectopic pregnancy with a large amount
of clot around it.
And if this complex mass is tubular, remember
that you're likely looking at a hematosalpinx.
So a fallopian tube that has filled up with blood due
to the central ectopic pregnancy within the tube.

Heterogeneous Mass and Hematocelpinx

Here's what I mean by a heterogeneous mass.
This is a patient who's at 5.7 weeks based on IVF.
Here's the ovary, here's the edge of the uterus,
and we can see this solid nondescript hypoechoic mass
separate from the ovary, separate from the uterus,
two centimeter mass.
This is the ectopic pregnancy in a different patient.
We can see the ovary here
and this tubular,
somewhat echogenic structure in the adnexa.
And if you look closely at this tubular hematosalpinx,
you might appreciate that there's a little echogenic ring,
almost like a donut right in the middle of the structure.
And when we zoom up on that adnexal ring,
we can actually see that there are two gestational sacs,
and this is a twin ectopic pregnancy out in
that fallopian tube.
This is an old case,
but really illustrates
what we're looking at very well on the sagittal image.
In the adnexa we can see the echogenic ring
of our adnexal ring
within this larger heterogeneous mass.
And on that coronal image, you can see
that this is actually the wall of the fallopian tube.
Here's the gestational sac that's grown into the wall
or attached to the wall of the tube.
There's a little bit of bleeding inside the tube that
giving you the hematosalpinx
and also blood that has gone out.
The end of the tube is now in the peritoneal cavity
outlining the outside of the hematosalpinx.

Criteria for Diagnosing Ectopic Pregnancy

So what really are we looking at?
What are we looking for in the adnexa?
Well, there's a well-known paper in a Journal of Ultrasound
and medicine in 1994,
which is a meta-analysis of 10 studies.
And in that meta-analysis, the authors found
that the most appropriate criteria
for diagnosing an ectopic pregnancy is any
non-cystic, extra-ovarian adnexal mass.
So think about that. The mass cannot be on the ovary,
so anything not on the ovary, but it also can't be a cyst.
So it cannot be the typical simple paraovarian cysts
that we see all the time crossing off the cystic structures,
crossing off anything in the ovary.
If there's anything else left in the adnexa,
that's the ectopic pregnancy.
And when you look at these non-cystic adnexal masses,
there's a sensitivity reported of almost 99%
and a positive predictive value of 96%.
This study was re-looked at in 2005
and the numbers, if anything, are better,
almost a hundred percent sensitivity,
positive predictive value, again, well over 95%,
93%
and a negative predictive value of almost a hundred percent.

Example of Adnexal Mass

So here's another example of an ectopic pregnancy.
The ovary is here
and there's a big mass here,
which is very echogenic ill-defined.
Doesn't really look like a gestational sac,
but certainly is a mass in the adnexa.
It's not a simple cyst, it's not on the ovary.
You can see we're pushing on it here.
It's very ill-defined.
It doesn't have a lot of information, pretty close
to the ovary, a little bit of free fluid
and a video clip through the mass showing the ovary here.
But look closely at this mass, look very closely
watch the whole clip.
Right at the end of the clip is this,
here's the tubal pregnancy right here,
and if you look at it, I'll put my arrow right on it.
It's right there, right at the end.
There's a little tiny sac in the middle
of this enormous clot.
So look carefully when you see these big masses,
sometimes your answer is right in the center.

Echogenic Lesion Example

In comparison, in this other patient with ectopic pregnancy,
we do again see an echogenic lesion in the left adnexa.
And on this clip you can see
that there really is nothing within it.
And this is just a collection of trophoblastic tissue,
that bright echogenic trophoblastic tissue in the hematosalpinx
and free fluid with echoes around the lesion.
So less specific,
but just as suspicious for the ectopic pregnancy.

Movement of the Mass

So things to think about when you're looking at the adnexa
and you find a mass.
One question is, is this mass part of the ovary or not?
And that's a useful thing
to help you decide whether you are concerned about an
ectopic, but also look at the mass
and determine what the echo texture of the mass is.
So what do I mean by movement of the mass?
Well, if you, during a transvaginal scan,
place some pressure on the patient's anterior abdominal wall
as the vaginal probe is on your lesion
and push, you can see here that the ovary stays lateral
and the ectopic pregnancy slides away and slides medially.
So this shows us that this lesion is not part of the ovary.
It moves separately from the ovary.
In comparison, this patient
who has a complex lesion on the medial edge of the ovary,
when we push the lesion sticks with the ovary,
it all stays together.
We cannot separate this off the ovary, and that's
because this is the corpus luteum, not an ectopic.
When you look at movement of an adnexal mass, the majority
of patients with ectopic pregnancy did show movement
of a mass with palpation.
A few patients without ectopics also showed movement
of the mass with palpation, potentially
that was some hematoma
or some normal fallopian tube
that can slide away from the mass.
So that is a reasonable thing to do to
help you determine whether the lesion is
part of the ovary or not.

Case: Empty Uterus with Adnexal Mass

Here's a patient with an empty uterus, no intrauterine
or gestational sac.
Here's the ovary. So we do see a mass next to the ovary.
And again, when we use pressure, you can see
that the ovary slides,
but this adnexal mass rolls, it would be impossible
for a cyst, a corpus luteal cyst on the ovary
to turn or roll.
So that motion, even though we're not really separating
them, we can see the mass move,
whereas the ovary slides away.
So that confirms our suspicion of an adnexal mass
and an ectopic pregnancy.

Case: IVF Patient with Heterotopic Pregnancy

Here's a patient who came in a few years back
with persistent abdominal pain, having undergone IVF,
and she was told at an outside hospital
that she had an intrauterine pregnancy.
And indeed we do see an intrauterine pregnancy
with at least one yolk sac, potentially two yolk sacs,
but she's still having pain
and notice there's quite a bit of free fluid
over on the right side of her pelvis.
So out in the right adnexa, she had an enormous
heterogeneous complex mass.
This is where all her pain was.
And looking at the mass I was able to appreciate, I thought,
well, let me see if I can find the ovary inside this mass.
Is this just the ovary
that has a hemorrhagic corpus luteal cyst
or is this a problem?
And inside the mass, I could see this hypoechoic ring
and an echogenic ring both turning on the color.
You can see color flow here
around the patient's corpus luteum.
This is the right ovary
and right next to the ovary, an echogenic ring also
with a little bit of blood flow.
And this is her heterotopic pregnancy, creating a lot
of clot around the right ovary.

Differentiating Tubal Ring from Corpus Luteum

Well, when we are trying
to figure out whether we're looking at a tubal ring
or a corpus luteum,
we did do a study a few years ago looking at the
echogenicity of the tubal ring in comparison
to the echogenicity of a corpus luteum.
We had 26 patients in that series who had a tubal ring
with a yolk sac or with a heartbeat.
And of those 26 patients, 88% of the rings were brighter
or more echogenic than the ovary.
We also had 13 patients with empty rings, no yolk sac,
no heartbeat, no way
of knowing whether this was truly an ectopic.
And yet 77% of those patients, the ring
was more echogenic than the ovary.
We had a control group of 45 patients
with a normal intrauterine pregnancy and no ectopic.
And in those patients,
the corpus luteum was more echogenic than the ovary in
only 3%.
So the vast majority of corpus lutea are isoechoic
or hypoechoic.
The vast majority of ectopics are echogenic.
This is what I mean. These are patients from our series.
Here's the ovary here, and here's the echogenic tubal ring.
And you can see that the wall
or this ring is clearly much brighter than the
parenchyma of the ovary.
In comparison, here's the thick walled corpus luteum
hypoechoic in relationship to the
to the echogenic ovarian parenchyma.
So the relative echogenicity
of an adnexal ring can be a very useful characteristic if
you can't figure out based on location,
whether you're looking at a tubal ring or a corpus luteum.
Another paper looked at this
where they compared the echogenicity of the ectopic
and the corpus luteum to the endometrial stripe.
And in this study they found that the wall of the
of the tubal ring
of the ectopic was brighter than the endometrium in 30%
of the ectopics, but none of the corpus luteal cysts,
the wall of the lesion was less echogenic than the
endometrium in a third of ectopics,
but in the majority of the corpus luteal cysts,

Case: Overnight Resident Evaluation

here's a patient that was seen overnight a few years back and one
of our residents took this transvaginal image showing an
intrauterine pregnancy.
There's a yolk sac and there's a heartbeat of 106
and out in the adnexa, here's the right ovary.
And they found this lesion out in the right adnexa
with an echogenic ring around it
brighter than the ovarian parenchyma.
The resident was very concerned
that this was an ectopic pregnancy
and the patient was taken to the OR.
Well, there's a couple problems with that scenario.
One is if we look closely at this echogenic lesion,
we can see that the ovary itself goes all the way
around the echogenic lesion.
And this is clearly an intraovarian cyst,
not a non-ovarian lesion.
So that's one reason why we shouldn't be
concerned about an ectopic.
Number two, the patient has an IUP, so they're less likely
to have an ectopic pregnancy.
Number three, the third problem with this case is
that the patient went to the operating room even
with a completely stable clinical picture.
No free fluid, normal blood pressure.
This patient probably should have been watched
rather than taken to the
OR emergently in the middle of the night.
And this is what happened when they got to the OR here's the lesion, you can see that it is,
this is the ovary here,
and this lesion is clearly intraovarian.
And it was simply the corpus luteum.
And here's the uterus here.
Now this patient did fine
and the intrauterine pregnancy continued normally,
and the gynecologists were clearly not, did not
remove the corpus luteum and that just closed up
and the patient went home.
But it's important to remember to use the echogenicity
and the location of the lesion, not one over the other.

Doppler Evaluation

Now, when we are looking at a tubal ring versus a corpus
luteum, what about doppler?
Can we do doppler of the lesion
and help us distinguish
between an ectopic pregnancy or a corpus luteum?
Well, the resistive index
around an ectopic pregnancy is widely variable
and can go from 0.1 to 1.6.
That's a huge span as opposed
to the corpus luteal resistive index, which is much lower,
somewhere between 0.39
and 0.7.
So it did show us that an RI
of greater than 0.7 was a hundred percent specific
and had a positive predictive value of a hundred percent.
But that's not that useful
because only one third
of the ectopics in this study did have
an RI that was that high.

Free Fluid and Hemoperitoneum

Well, here's another finding we can look for in the adnexa.
What about the presence of free fluid?
What's important when we look at fluid in the cul-de-sac in
a patient at risk for ectopic pregnancy
to determine whether there are echoes in the fluid
or whether the fluid is anechoic?
The reason is that when there are echoes in the
intraperitoneal fluid, there's a very high correlation
with hemoperitoneum.
And that suggests to us that the patient,
this patient is at very high risk for an ectopic pregnancy.
And this is an old paper from 1991,
but has stood the test of time In 1998,
an article in JAMA looked at 185 patients who were taken
to the operating room for ectopic pregnancy.
In those patients, 125
of the patients had echogenic fluid
at the time of the ultrasound.
And over 98% of the patients' blood was found at surgery.
In the 30 patients with anechoic fluid, zero had blood.
And in the 30 patients
with no fluid at transvaginal sonography, zero had blood.
So this tells us, this confirms
that echogenic fluid in the cul-de-sac does correlate
with hemoperitoneum in patients with ectopic pregnancy, with high sensitivity specificity
and positive predictive value.
In another study done in the annals of the American Journal of Emergency Medicine, 38%
of patients with pregnancy of unknown location
had isolated free fluid.
Of these 38 patients, 42% ended up with ectopic pregnancy.
About a quarter of those had a moderate amount of fluid
and three quarters of the patients who presented
with a large amount of fluid.
So it does tell us that patients
with isolated cul-de-sac fluid are at a moderate risk
for ectopic pregnancy.
And if the fluid has echoes in it
or if there's a large amount of fluid,
we're gonna be more worried about those patients.

Case: Complex Fluid

Here's a patient who presented at 5.4 weeks
and out in the left adnexa we see complex fluid
Ill-defined maybe sort of clumping up here suggesting a clot.
And on the right side, a large amount of fluid
with low level internal echoes.
And this patient in this patient, this was the only finding
of an ectopic pregnancy.
We could not find a mass,
we could not find an intrauterine pregnancy just echogenic
hemoperitoneum.

Missed Ectopic Pregnancies

What about the patients with a completely negative exam?
Well, why do we miss ectopic pregnancies?
It could be because the pregnancy is extremely early.
If the pregnancy is under five weeks, these are very,
very small, and it could be too early for, it's too early
for us to see in the uterus.
It could be too early for us to see in the adnexa patients
with a high BMI patients with a lot of fibroids,
inexperience of the sonographer
or patients who have pathology in the ovaries
make it difficult for us to find the ectopic pregnancy.
5% of the patients in our series had zero findings at
their pelvic ultrasound.
If the patient is stable in this instance,
the most important thing
to remember is you haven't found an ectopic.
Just get follow up ultrasounds and HCGs
because we need to make sure that
that patient does not have an intrauterine pregnancy.
If the patient is unstable, she has
to go to the operating room.
Whether we found the problem
or not, here's a patient in whom the presence of pathology in the ovary made it very difficult
for us to make the correct diagnosis.
This is a patient who had undergone IVF
and following the IVF had hyperstimulation.
And you can see on this clip
that there are very large cysts on the ovary,
the ovaries sitting down in the cul-de-sac,
and we have free fluid again, all related
to the hyperstimulation on this video clip.
I don't know if anybody has noticed anything going by,
but when we look a little bit closer,
you may or may not see it.
Now here's the big cyst on the ovary,
and here's a little complex lesion with maybe
a little flicker.
And here's the zoomed up image.
And now it's easier to see the echogenic ring, the yolk sac,
the embryo and the heartbeat.
But I will say in view of the large cysts on this ovaries
and the known hyperstimulation,
we did not immediately see this.
And the patient went to the OR for persistent pain.
This turned out to be a primary ovarian ectopic,
and we were completely thrown by all
of the other pathology in the ovary
and missed this little tiny ectopic sitting on the edge.

Tubal Rupture

What about tubal rupture?
You hear a lot of conversation about tubal rupture
with ectopic pregnancies or ruptured ectopics.
And remember when you talk about a ruptured ectopic,
you're not talking about the gestational sac itself
that has popped for some reason and the yolk sac fell out.
We're talking about the fallopian tube that ruptures
and with the gestational sac inside, we care about it
because there is an increasing trend across the world toward
medical management of ectopic pregnancy.
And if the patient is going to be managed nonsurgically,
it's very important that we know
that the fallopian tube is intact.
So can we help? Can transvaginal sonography tell the
referring gynecologists whether the
fallopian tube is intact?
We, in our retrospective study, we had patients
who had ultrasounds within 24 hours of their surgery,
and all of the patients had ectopic
pregnancy proven at surgery.
This study was composed of 143 patients,
and at the time of surgery, 75% were unruptured
and 25% were found to be ruptured at pathology.
When we looked at those 143 patients
and we divide the ultrasound findings
to whether there was a cardiac activity, a yolk sac,
just a tubal ring, a generic looking mass
or no mass at all,
the rupture rate in these categories was not significantly
different between any of the categories.
There is no statistical significance based on
what the adnexal mass looked like
or even whether there was a mass at all.
It turned out that the rate
of rupture in our series was significantly higher if the
fluid was moderate to large, a third
of those patients were ruptured as compared to the patients
with small or no free fluid.
Only 17% of those were ruptured.
However, moderate to large fluid had very poor sensitivity
for tubal rupture
and a very poor positive predictive value.
What about HCG levels?
Can we look at the HCG level
and determine whether that patient has a ruptured tube?
We had 139 patients who had an HCG within 24 hours
of their surgical confirmation of ectopic pregnancy.
And it turns out that there is no cutoff level
that predicts tubal rupture.
And interestingly, approximately 10% of our patients
with very low HCGs did have rupture of the tube at surgery.

Similar Ectopic Appearances

Here's two patients with very similar ectopic pregnancies.
Here's the ectopic.
Here you see the bright echogenic ring in the central yolk sac
in this patient, the bright echogenic ring.
Here's the yolk sac. These look very, very similar to me.
Sonographically. One is ruptured and one is not.
The answer is this is the ruptured ectopic.
Clearly we cannot tell the difference based on the
sonographic appearance.
So remember that tubal rupture is possible when we don't see
a mass at all or when there's little or no free fluid.
There's no single appearance that we can see at sonography
to guarantee no tubal rupture,
and there is no single HCG level that we can use
to completely exclude a tubal rupture.

Role of 3D Imaging

So last but not least, finishing up, what about the role
of 3D imaging and 3D imaging can be very helpful when we're looking at the
more unusual types of ectopics.
In other words, cornual ectopics, tubal ectopics
or normal implantation.
It's useful with cervical pregnancies
and particularly useful with c-section ectopic,
C-section implantations as well.

C-Section Scar Implantation

So here's a patient with a retroverted uterus
and we can see this big echogenic lesion in the
lower uterine segment.
And because the patient is retroverted, we know
that this is the site here.
This is the anterior surface of the uterus.
This is the site of the prior cesarean section.
This is where the C-section scar is.
And this pregnancy is almost certainly
a cesarean section implantation.
And on the video clip, we can see the pregnancy with,
we can see the bulge of the anterior myometrium.
And with color doppler, we can see blood flow going out
around and extending to the surface of the uterus
that the whole placental
or trophoblastic tissue has penetrated the myometrium.
And on this 3D coronal reconstruction, here's the fundus
of the uterus up here.
The pregnancy is clearly not at the fundus
and this picture has been rotated.
So this is the back of the uterus
and this is the front of the uterus.
And we can see that the myometrium is completely disrupted
here in the lower uterine segment.
And the pregnancy sac is bulging out of the cesarean section scar.

Follow-Up Case: C-Section Scar Question

Here's a patient who came in at five
and a half weeks with a question
of a c-section scar implantation.
So the uterus is here,
the fundus is up here down in the cervix,
and this is the region of the C-section scar.
And indeed this gestational sac is quite low
in the lower uterine segment.
And the question is, is it possibly going up into this
c-section scar or not?
So what do we do? The patient's asymptomatic,
we're gonna follow this patient up and here she is at six
and a half weeks, so a week later.
And here's the 3D reconstruction anterior view.
You can see the pregnancy sac still in the lower uterine
segment, but to really know whether the cesarean section
scar is involved, we have to rotate the image so
that we can look at the anterior surface of the uterus.
And here's the cesarean section scar right here.
And you can see that the gestational sac is seated well away
from the scar.
I will point out however, that on 2D imaging,
we can see the cesarean section scar right here,
right here, and the gestational sac well above the level
of the scar with 2D imaging quite clear as well.

Cornual and Interstitial Pregnancies

What about cornual implantations
or the true interstitial pregnancies?
Here's the uterus, the endometrial cavity,
no gestational sac seen there.
Up at the right cornua
or the right fundus, we can see the pregnancy
with the echogenic rim
and embryo cardiac activity.
And here's the myometrium heading out
and around at least one part of this pregnancy sac.
Lots of color flow seen around the implantation.
And when we push, we can't really separate this pregnancy
from the bulk of the uterus,
you can see it's certainly separate from the
endometrial cavity.
And on the 3D coronal reconstruction, you can see
that the pregnancy is disrupting the myometrial surface at the right fundus.
So it's a true interstitial or so-called cornual ectopic.
Another patient with a cornual implantation.
This one is a little tougher
because if you notice on the video clip,
the endometrial stripe is diverging.
So we're looking at possibly a sub septate uterus.
And in that instance, you wanna be careful
because you're gonna have some asymmetry
and the sac can be located well off to one side or another.
The issue becomes whether there's myometrium all the way
around the pregnancy,
whether the pregnancy is still in the
endometrial cavity or not.
And here 3D became very useful to us.
So you can see on the reconstruction
that the patient does have a sub septate uterus
with a big piece of this fundal myometrium diving down into
the endometrial cavity.
But we can also see that at the right horn that
or out at the right cornua,
that the endometrial cavity ends here.
And the gestational sac is separate from the endometrial
cavity and partially covered by a very thin,
thin myometrium.
And this was a very useful time
for 3D imaging when you have an anomaly of the uterus
and a pregnancy, not smack in the center
of the endometrial cavity in comparison to this patient
where we can see the endometrial cavity
and we can see the pregnancy
that is not in the endometrial cavity.
And on the 3D reconstruction, here's the gestational sac
sticking onto the left cornua.
Quite a bit of myometrium here,
quite a bit of myometrium here.
The question is, is this myometrium coming out and around?
And this 3D image was actually a little bit misleading
because when we pushed on this pregnancy,
we could actually see that the pregnancy moved
separately from the uterus.
And this is an intramural ectopic pregnancy
or pregnancy in the part of the fallopian tube.
Very close to the uterus,
but not the interstitial component of the tube.
Just really, really close by to the uterus
and just a tubal pregnancy which mimics a cornual ectopic on the 3D imaging.
So make sure that you use all of the tools at your disposal.

Conclusion

In conclusion, transvaginal sonography continues
to be the optimal method for evaluation
of ectopic pregnancy.
Early diagnosis
of ectopics allows less invasive treatment
options for our patients.
It's important to do a close evaluation of the endometrium,
a close evaluation of the adnexa using palpation.
And 3D imaging when necessary
and critically important, the stable patient
with a pregnancy of unknown location
follow up is best in that patient.
Thank you very much.